Deciphering the potential of potassium-ion batteries beyond room temperature.

Alloying-type anode materials are considered promising candidates for next-generation alkali-ion batteries. However, they face significant challenges owing to severe volume variations and sluggish kinetics, which hinder their practical applications. To address these issues, we propose a universal synthetic strategy, which can realize the facile synthesis of various alloying-type anode materials composed of a porous carbon matrix with uniformly embedded nanoparticles (Sb, Bi, or Sn). Besides, we construct the interactions among active materials, electrolyte compositions, and the resulting interface chemistries. This understanding assists in establishing balanced kinetics and stability. As a result, the fabricated battery cells based on the above strategy demonstrate high reversible capacity (515.6 mAh g), long cycle life (200 cycles), and excellent high-rate capability (at 5.0 C). Additionally, it shows improved thermal stability at 45 and 60 °C. Moreover, our alloying-type anodes exhibit significant potential for constructing a 450 Wh kg battery system. This proposed strategy could boost the development of alloying-type anode materials, aligning with the future demands for low-cost, high stability, high safety, wide-temperature, and fast-charging battery systems.